import java.util.Scanner;

/**
 * Created by Salted fish
 * Description:
 * User: 24539
 * Date：2021-07-29
 * Time: 22:03
 */
public class Test {
    public static void main(String[] args) {
        int[] arr={1,1,2,2,3,4,4,5,5,};
        fn(arr);
    }
    public static void fn(int[] a) {
    for(int x=0;x< a.length;x++) {
        int count = 0;
    for(int y=0;y<a.length;y++) {
        if (a[x]==a[y])
            count++;
        }
        if(count==1)
            System.out.println(a[x]);
    }
    }
}